Method of molding articles with inserts



July 18, 1933. F. J. WALLENBERG METHOD OF HOLDING ARTICLES WITH INSERTS Filed Jan. 9, 1929 MW #TTUF/Vffi Patented July 18, I

UNITED s 'rA FRANK a. WALLENBERG; or "I ONAWANDA, TERMINAL ooRronA'rIon,

NEW Yomr; nssienon To ny A TERY or BUFFALO, nEw Yonx I I METHOD or iuoLniive ARTICLES was INSERTS Application filed January 9 This invention relates to articles molded from plastic material and having therein a reinforcing insert, and particularly to the method of floatingrthe insert into the interior of the article. The reinforcing inserts are usually of metal or other material which might deteriorate when exposed to air or to various acids or otherchemicals. I-Iereto fore it has been difficult to entirely enclose the insert in the body of the plastic material, and have it located in a desired and definite relation to the walls of the article.

An object of this invention is to provide an improved method of floating areinforc'ing insert into the interior of an article molded from plastic material; with which the in-- sert' may be definitely located with respect to the walls of the article; with whichlthe, insert may be completely enclosed within the article and protected thereby, and which will be relatively simple and inexpensive.

p A further object of theinvention is to provide, an improved method for floating an insert'into a molded article in a simple-and rapid manner, and Which may be performed with relatively inexpensive apparatus.

Various other objects and advantages will be apparent from the following description of one example of the practice of the invention, and thenovel features will be particularly pointed out herein'afterin connection with the appended claims.

In the accompanying drawing V Fig. l'is an elevation, partly in section, of

the dies used in the preforming operation. and illustrating one stepin the process;

Fig. 2'is a similar elevation, but with the. die elements in pressing relation to one another;

.Fig. 3 is an elevation" partly in section of another set of die elements which may be utilized in performing a subsequent ste the process, the'die elements 'b'eing'assem led ready for a pressing operation;

Fig. 4 isa similar: elevation, but with the die elements in pressing relation to onean 7 other, the pressing operation being partially completed;

Fig. 5 is a similar elevation, bu 50 pressing operation completed;

with the oblique walls 6. y I

osition, the insert or ring will I or plate8 by which it is moved downwardly 1929. ser iain 331,361. .1"

Fig. 6 is a plan of'the lower die element a used in the final pressing operation"; and

F ig. 7- is a sectional elevation of the lower i die element shown in Fig. 6,' the section being taken approximatelyalongthe line '7-7 of Fig-6. I a".

In the illustrated j example of the practice of the invention, the article 1. (Fig- 5) to be formed, is a clamping ring used as; a part" of a battery @term'inal connector. ;Such a ring must have tensile strength fag'ainjst stresses tending to distort thering or break i. it, and for that reason jis provided with a reinforcing insert 2 in the nature of an annu lar ring Such a" ring must-be compl'e'telylu5 enclosed in the material ofthe article in order to be completely'protected against the action] of battery acids or chemicals, and the plasticv material selected for'such' anexample' isone which will be inert to the action of'battery acids or ,chemicals. j l

According to the improved methb' se'rt or ring 2is dispose in thejpressure chamber?! of apre-forming die elementjg l and supported in that chamber intermediate the ends ofvvthe same in any suitable manner,

such as upon upon a shoulder 5 formed be-: tween two sections of the: chamber which-may beof difi'erent widths or diameters; The I shoulder 5 preferablyv merges into the larger section of, the chamber byan oblique wall '6,

so that when the ring or insert 2 is disposed? in the larger section of the chamber 3, it,

will'be guided automatically into. the de-; sired position 'uponthe shoulder by the;

In such, a p 7 be supported solely upon one of its ends, and both faces as'well as the opposite end of the ring willbe spaced from the walls of the cham- 1 ber 3. The chamber 8 is then filled withloose plastic material, as illustrated in Fig. 1.' A' suitable die element 7 y is mounted'upon a'base" into and out of in Fig. 2." 1

In the particular illustrated example, the die element 7 has a reduced projecting end 9 which isadapted to produce a cavity in the molded article when thelarger section of the the die chamber3, as shown upper die element enters and closes the upper 3 end of the chamber 3. Theloose material is partially compressed in the chamber 3, so as I to be given a form and shape designated by the object A in Figs. 2 and 3'. 7

When the loose material'is compressed into the lower end ofthe chamber-3, it will be packed around the exposed surfaces of the insert or ring 2, and the plastic material thus compressed will adhere to the'lnsert and com 'pletely enclose it except for the edge orsur-' face resting upon the supporting shoulder 5.

The upper die element 7 is then removed 3' chamber correspondingto. the desired outer. surface'of the finished molded article, and in i 2 the particularexample,the cliamberma has -pressed around thesidesof the ring or inse'rt willserve to space the insert from the ,;tofbe formed in the finalniolded article. I After the partiallyformed object A has been placed inthe'l'ower" die element 10, as

from the chamber 3, whereupon the lower die'element 4 is inverted, and the part ally formed object A pushed or knockedcout of the die, chamber through the, larger end...

thereof.

[The object A, which is sufiiciently compact tolhold its; shape, is then placed in a final forming die element 10, Figs. 3 to 7. The die element 10 has aninterior opening- 10a or a reduced lower end. The partially formed oibject'A may 'besligh-tly smaller than the cavityior chamber 10min the die elementlO, but the plastic material which has been comside walls of the cavity orcchamber of the die element 10, as shown clearly in Fig. 3.

The other die element llof the final forming'die mayhave any desired shape, suchas a reducedprojection 12. Thereduced prejection" 12 is provided in this particulars ample because a reduced cavity or passage. is desired in. one section of the annular ring. or article l when finally completed. If such a reduced terminal is not desired inthe molded I. article, the reduced projection 12 may of course beomitted, the upper die element being always glventhe shape and SlZflbftlle cav ty illustratedin Fig. 3, the upper die element 11, is broughttowardsthe lower. die element and forced under high pressure into the'par tially formed object A, as shown in Fig. 4.

Theupperdie element ll is carried by plate 13, and as the plate 13 oand die'element descend, the die element will enter the cavity lof .the partially formedobject A which Was formed by the-reduced projection 9' in the pre-forming die element.

The die element 11 in enteringthe ect A may displace some of the plastic material into engagement with the lateral'wallof the lower die elementto give a desired shape to thearigticle and to perfectly center it, and as the This serves tocen terthe object A and hold it against lateral displacement as it is being compressed-into: ilt-the die element 10.

upper die element continues to, descend, the material forming the object A will be also engaged by plate 13 and further compressed r 1I1t0 a more compact mass, while the die element forces its way farther downwardlyinto or through the object A. The'portion of the object A having the insertor ring is within I the cavity of the lower die element 10 when first assembled therein, as in Fig. 3, and since the ring or insert 2 cannot be enlarged by the pressure on the plastic material, the material oftheobjectfA when compressed will be forced farther around the ringer insert.

material will be forcedaround the ring from both directions, and willfinally meet and.

partially around the ring unite so that the ringiwill then be completely enclosed by the plastic material as though floating in the plastic material, but owing to the density of the materialand thepressure underwhich it isheld,.the ring[will have no opportunity to settle orchange its position materlally,

As the pressure continues, the plastic material will be further'compressed into a still i more compact mass, until finally the die ele- I ments reach the position shown in F ig., 5.

With the die elements 10 and 11 remaining in the relation toone another shown in Fig. 5,. the plastic material is-allowed to harden, andthereafter the die elements 10 and 11 may be from the lower die element 10.

separated and the molded article 1 removed" Any suitable plastic material may be util-i ized, dependingupon the particular article to be formed or molded. For example,va-

rious plastic materials having as their base, a phenol condensation product, with or without a suitable; filler, and the various hard rub her and asphaltic plastic materials and com positions, are alleasily molded in this manner.

L It will understood,:however, that these A materialsor compositions are cited merely as;

examples, and that any other suitable plastic inasmuch as the invention relates primarily to the manner of floating the'insert into theplastic'material, and is not necessarily limited Y to the particularplastic material which may be selected for use. Y 7

Inthe illustrated example of'a battery at minal connector, whereconsiderable strength isdesired and brittleness is not desired. the

filler used may contain textile Zfib'res, Such a composition maybe in-aloose, dry form, and assuchmay be quickly and easilyplaced in the pre-formed, die chamber 3.

lThe chamber 3 may serve as a gage'for materials or compositions may be employed,

' For the particular'article being misses 1 l measuring out the properamount of the materiallfor each article. A'nyi' excess'will of course squeeze'out'as flash in the final press ing or molding operation. In some instances" wherethefiplastic material must-beheated in order to flow freely;durin'g the molding op-f eration, the" die elements 10 and- 11 maybe heated during the pressingoperation. i a

molded,

andwhich has been selected asan example' for the purposes of illustrating the invention, the lower die, element 10=has a flatnwall' 14:, Figs. 8, 6 and 7, and thisfiat'wall islocat-ed as a" chord at one side oflacylindrical chamber. To simplify the formation of this flat Wall in the die element, the chamber may first be made cylindrical, a slot 15 then milled v into the upper surface of the die element, and

a plate 16 disposed edgewise in this slot 15'. The plate"' 16 will then 'eXtend chord-like across the cylindrical chamber and form the flat Wall atone sidez 'thereof.

a The diee'lement 10 may be confined suitable base 18, and the plate 16 confined in the slot 15, by screws 17 which are threaded into the base18,with:the heads of the screws slightly overlapping or overrunning with the die element and the plate 16 as shown inFig; 6i The'upper and lowerfaces of the die ele -f ment '10 may also be bevelled away from a narrow,.c1rculaf band along the nner space or cavity, so as toinsurea' more perfect and continuous Contact therewith-of the base-18 and the plate 13, which more-perfect contact reduces the amount of flash-which may'form during the final pressing operation. j i

It will be observed thatthisprocess may be rapidly and easily performed, and-that the insert or ringwill be entirely enclosed in thefinal article, so as to belprotected'bythe n plastic material thereof. It will valso be observed that the partially molded material forming" the pro-formed object A, serves as a spacer for the'insert and holds it properly, spaced duringfthe' final pressing operation'in which the plasticmaterial is then forced combletely aroundothe insert! J The method is applicable to the molding of articles of various forms and sizes into which a reinforcing insert is to be floated or suspended.

I vention as Various changes in the details, which have been herein described and illustrated in ors d'er .to explain the nature o-f the improved method,n1ay be made-by those skilled in the art withinthe principle and scope of the inexpressed in the appended claims I claim 1. The method of floating a reinforcing insert into the interior of'an article molded from originally loose dry plastic material,

-which comprises placing said insert in' a cavity, compressing a measured quantity of said loose material partiallyaround'said insert in said cavity and partially compacting a, and r then with the said sat s; spacing? the insert from ,molding dies/further com-"1* pressing and compacting the same materlal",

in said dies and forcing it completely around 2. The method of flo'ating a reinforcing i and inclosing'the insert;

sert into'the interior "of an artiolemolded die," then,- while the insert is so supported, compressing said material flto mold it"{about' the exposed surfaces of the insert, then, with 'thd'material' spacing the 'ins'ertj-ifrom "the; walls of-agforming die, further and completely compressing the same material and forlci ng' it completely around and 'incl'osingthe insert? fromdry, loose plastic materiaLwhich come.5

prises'supportingsaid'insert ina pre-formi'ngf insert into the interior of an article molded from plastiematerial which comprisessupporting the insertb-etween-the-endsof apre-f forming die-and'withinthe chamber-of the die, directly upon a; wall thereof and molding and-partially com pri's'in ga measured 5 quantity of the materialfaboutfthef exposed 5 surfaces of-the insert and in opposite direq v vtions beyond said -insert, then,-; withthe molded] material spacing the insert'fromthe I \jwallfs'of a form'ing die, completely cornpressing the" same' ma'teri-al and forcing. it completely around and mclosmg the insert.

4Li The method of ifioatir g anopenended reinforcing insert into theinterior of an-ar 7 ticle ymolded from plastic material, which comprises supportin said insertatone end;

is located intermediate the ends of the die upon ashoulder of a p're-forming'die which chamber, moldingthe material about the ,ex-

pletely around the insert.

Th metli a offlo rin a a'e e eaa ak I reinforcingin'sert into'the interior ofana'r ticle' molded from. plastic material, which comprises supporting said insert at one end upon a'shoulder. of a pi'eaforming die which is located intermediatevthe-ends of the die chamber and with the outersurface partially spaced from the side wall of theidie, molding the material aboutthej exposed surfaces of .posedsurfaoes oftheinserg then placing the I molded-material" and insertin aforming die 1 r with the material spacingthe insert from the walls offthe die, and then completely coin-I. pressing; the j'mat'erial j;and forcin itgeomthe insert, then placing the molded-material measuredquantity-of a relatively loose dry ing the material in said chamber to partially enclose the insert, removing the insert and material, andv placlng -1t 1n a forming die n Which the compressed material spaces the-insert from'the formingcdie' walls, and then further compressing and compacting the same material to force it completely around 7 the insert and into the desired form.

1 7. The method of floating a reinforcing-insert-into' the interior of an' article molded from plastic material, which comprises supporting said insert in the chamber ofaprey forming die, with, a portion of its surfaces;

I V exposed to the chamber, supplying a selected 'quantity'of the material {to the chamber, compressing and-compacting the material in the chamber to form a rigid coherent object with the' material thereof partially enclosing said insert, removing said object and placing-it in .lanother" d-ie chamber. which 'is' of greater lateral dimensions thanthe pre-forming die with the inert spaced from the walls of the second die chamber by thefcompressedmaterial, and further compressing the object in the second die chamber to "force the same material thereof against the walls of that {chamber and completely around the insert. j r

' BfThe method of floating a reinforcing insert into the-interior of an article molded from plastic -material,which comprises supporting'said insert in the chamber of a preforming die, with its sidespartially spaced from the walls of the chamber, supplying-a selected'quantityof' the material to the chain'- ber, compressing and compacting the mate-: rial in the chamber to form a coherent, shaped retaining and smaller object with the mate- I rial thereof partially enclosing: said insert, v removing said object and placing it in another die chamber which is of greaterlateral difmentions than the preforming die with the. c insert spaced from the wallsof the second die chamber. by the compressed material, and furtherc ompressingand compacting the object in the second die chamber to force the w same ,material thereof against the walls of that chamber and Completely around the inf-q i .7

.9. The methodof'molding an articlewith a completely enclosed insert, which comprises supporting the insert in a chamber larger than said article with the. insert projecting E76 7 a into the chamber, placing in the chamber a selected quantity of loosemolding material,

'compressingthe material in the'chamber to compact it and cause it to surround and tight- I ly engage the projecting part of the insert, placingthe insert and attached molding material in a'chamber.in'whichthemolding ma-' terial spaces the previously projecting part 1 of the insert fromthe walls o-fthe chamber, and then forcing the'same molding material around the exposed surfaces of the insert and further compacting it, soasto enc-ase' terial and increase the density of saidma terial.

1 0; The method of molding an articlewith a completely enclosed insert, which-comprises.-

supporting the insert in achamber with part of the insert proj ecting] into :the chamber, placing-in the. chamber. ai'selected quantity of dry, loose molding material, compressing the completely the insert in the-molding ma moldingmaterial in said chamber until the material iscompacted and enclosesand is attached'to the projectingpart of the insert and formstherewitha rigid, coherent objecit, and th n, while usingthe compressed molding material to space the exposed part of the density and force it completely around the insert and completely'encase it. r e

11 The method'flof molding an: article with a completely inclosedinsert, which comprises compressing loosemolding material into a smallerand denser massand partially: inclose ing'said insert, then placing thepartiallyincased insert in-a. forming die with the insert) spacedfrom the wall of the die by the compressed molding malterial,sand; furtherr com pressing said material to-:force it completely around said insert and furtherconipact said material into a denser mass.

I xFRANK J. WALLENBERG; 

